Re: [RFC PATCH 1/2] dt-bindings: iommu: add bindings for sprd iommu

From: Rob Herring
Date: Thu Jan 07 2021 - 21:26:50 EST


On Wed, Dec 23, 2020 at 07:16:32PM +0800, Chunyan Zhang wrote:
> From: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
>
> This patch only adds bindings to support display iommu, support for others
> would be added once finished tests with those devices, such as Image
> codec(jpeg) processor, a few signal processors, including VSP(video),
> GSP(graphic), ISP(image), and camera CPP, etc.
>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
> ---
> .../devicetree/bindings/iommu/sprd,iommu.yaml | 44 +++++++++++++++++++
> 1 file changed, 44 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
>
> diff --git a/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml b/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
> new file mode 100644
> index 000000000000..4d9a578a7cc9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iommu/sprd,iommu.yaml
> @@ -0,0 +1,44 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2020 Unisoc Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iommu/sprd,iommu.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Unisoc IOMMU and Multi-media MMU
> +
> +maintainers:
> + - Chunyan Zhang <zhang.lyra@xxxxxxxxx>
> +
> +properties:
> + compatible:
> + enum:
> + - sprd,iommu-disp

Needs to be Soc specific. Is this block specific to display subsys or
that just happens to be where the instance is?

> +
> + reg:
> + maxItems: 1
> +
> + "#iommu-cells":
> + const: 0
> + description:
> + Unisoc IOMMUs are all single-master IOMMU devices, therefore no
> + additional information needs to associate with its master device.
> + Please refer to the generic bindings document for more details,
> + Documentation/devicetree/bindings/iommu/iommu.txt
> +
> +required:
> + - compatible
> + - reg
> + - "#iommu-cells"
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + iommu_disp: iommu@63000000 {
> + compatible = "sprd,iommu-disp";
> + reg = <0x63000000 0x880>;
> + #iommu-cells = <0>;
> + };
> +
> +...
> --
> 2.25.1
>